CS, why does something need to be in older seforim for it to be valid? Chasidus isn’t in any sefer before 200 years ago. The peleh yoetz was before that.
Halichos bas yisroel is full of sources. Rabbi falk’s isnt – he was writing mainly as an instruction guide, and most women aren’t interested in looking things up. Most women just want to know what to do and what not to do and not he concerned with the sources or even the reasons. I learned this the hard way when i was in shidduchim and afterwards; a simple “yes” or “no” is usually what they want.
The kitzur was written only 130ish years ago. And it was definitely not written for women.
Plus, all jewish women were tznius in those days. You didn’t need halacha shailohs and minimum requirements, because everyone was covered up and no one would dare do otherwise. There was absolutely no “fashion” industry and women didn’t wear clothes that were, to use an expression which somehow became popular among frum women, “flattering.” Take a look at pictures of European and sefardi jewish towns. More tznius than satmar! It was the הלוך ילך, the רוח אפינו – some things are so plainly obvious, so fundamental, that any simple jew knows them. Even the amei haaretz in chazal aren’t criticized for dressing untzius.
You’re defending the indefensible.
And to the point of being machshil others, LH only is machshil others if they believe it, and it’s not something the person walks around doing nonstop. A woman who walks around untzius will be machshil men every second of her life and amass boatloads of sins that will not he attoned for by asking your rebbe for forgiveness or learning his musings.